From: Dan Carpenter Date: Mon, 4 Dec 2023 12:29:00 +0000 (+0300) Subject: drm/bridge: nxp-ptn3460: fix i2c_master_send() error checking X-Git-Tag: v6.6.17~528 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c1074ae8180577f3ae8c565b93084cc60fc3d758;p=platform%2Fkernel%2Flinux-rpi.git drm/bridge: nxp-ptn3460: fix i2c_master_send() error checking commit 914437992876838662c968cb416f832110fb1093 upstream. The i2c_master_send/recv() functions return negative error codes or the number of bytes that were able to be sent/received. This code has two problems. 1) Instead of checking if all the bytes were sent or received, it checks that at least one byte was sent or received. 2) If there was a partial send/receive then we should return a negative error code but this code returns success. Fixes: a9fe713d7d45 ("drm/bridge: Add PTN3460 bridge driver") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter Reviewed-by: Robert Foss Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/0cdc2dce-ca89-451a-9774-1482ab2f4762@moroto.mountain Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/bridge/nxp-ptn3460.c b/drivers/gpu/drm/bridge/nxp-ptn3460.c index d819202..9b7eb8c 100644 --- a/drivers/gpu/drm/bridge/nxp-ptn3460.c +++ b/drivers/gpu/drm/bridge/nxp-ptn3460.c @@ -56,13 +56,13 @@ static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr, ret = i2c_master_send(ptn_bridge->client, &addr, 1); if (ret <= 0) { DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); - return ret; + return ret ?: -EIO; } ret = i2c_master_recv(ptn_bridge->client, buf, len); - if (ret <= 0) { + if (ret != len) { DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret); - return ret; + return ret < 0 ? ret : -EIO; } return 0; @@ -78,9 +78,9 @@ static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr, buf[1] = val; ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf)); - if (ret <= 0) { + if (ret != ARRAY_SIZE(buf)) { DRM_ERROR("Failed to send i2c command, ret=%d\n", ret); - return ret; + return ret < 0 ? ret : -EIO; } return 0;